Engine Identification

[Larry Hull]

I have a technical question that I hope someone can help me with:

I have a 1968 Chevy, Shortbox Stepside, with a 250 C.I. 6 Cyl., 3-Speed. The VIN numbers support the 250/3 speed..

This vehicle was originally from Georgia and brought to Canada 10 years ago.

The issue is – the original 250 motor was replaced with a Canadian motor, verified by the serial numbers. I want to procure an original U.S. block for my re-build and have conflicting information on what the “block numbers” should be.

I have an original 1968 Chevrolet Truck Chassis Service Manual and it states the following for block identification.

Engine Number:

F - Manufacturing Plant (F-Flint, T-Tonawanda)
12 - Month of manufacture (December)
10 - Day of manufacture (tenth)
FA - Transmission and engine type

However, according to American Classic Truck Parts – “Truck VIN decoder” for the 1968 model, the numbers are one of the following: ( TA / TC or TD )

1/2-Ton TA 6 250 155 8.5:1 1-bbl Manual
1/2-Ton TC 6 250 155 8.5:1 1-bbl Manual
1/2-Ton TD 6 250 155 8.5:1 1-bbl Manual

If the “T” stands for “Tonawanda”, what does the following number represent?

The Transmission coding is as follows – the “W, K or S, do not correspond with the Service Manual?

W N/A 3,4 speed Warner Gear
K N/A 3 Speed McKinnon
S N/A 3 Speed Saginaw

Can anybody give me some feed back?

Thanks,
Larry Hull,
Ottawa, Canada.